Wang Dong, Lian Jie, Wang Yuanzhe, Jia Peng, Gao Faming
Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-Utilization, Tianjin University of Science & Technology, Tianjin 300457, China.
Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
ACS Appl Mater Interfaces. 2023 Mar 29;15(12):15585-15594. doi: 10.1021/acsami.3c00912. Epub 2023 Mar 14.
Potassium-ion batteries (PIBs) are considered as a promising technology alternative to lithium-ion batteries due to more abundance of potassium than lithium and a lower redox potential of K/K than that of Na/Na. The critical limitation in PIBs is the electrode with poor rate capability and cycling stability induced by the sluggish reaction kinetics and large volume change during potassiation and depotassiation. In this work, we report a turbostratic lattice iodine-doped carbon (TLIC) nanosheet as an advanced innovative anode for PIBs displaying fast charge/discharge and electrode stability. The turbostratic lattice caused by doping of large-sized iodine and the unique charge transfer between iodine/carbon atoms creates more active sites and a shorter transport distance for K ions, improves the electrochemical activity, promotes rapid ion diffusion, and enhances pseudocapacitive behavior. The TLIC exhibits a high capacity of 433.5 mAh g at 50 mA g, an ultrahigh rate capability of 162.1 mAh g at 20 A g, and an excellent capacity retention of ∼96% (206 mAh g) after 4000 cycles. The combination of turbostratic lattice and pseudocapactive storage is an effective approach to designing carbon electrodes with the transformational performance of high capacity, rate performance, and long lifetime for practical applications of PIBs.
钾离子电池（PIBs）被认为是锂离子电池一种有前景的技术替代方案，因为钾比锂储量更丰富，且K/K的氧化还原电位比Na/Na更低。PIBs的关键限制在于电极，其倍率性能和循环稳定性较差，这是由缓慢的反应动力学以及钾化和去钾化过程中的大体积变化所导致的。在这项工作中，我们报道了一种涡轮层状晶格碘掺杂碳（TLIC）纳米片作为PIBs的先进创新负极，它具有快速充放电和电极稳定性。由大尺寸碘掺杂引起的涡轮层状晶格以及碘/碳原子之间独特的电荷转移，为钾离子创造了更多活性位点和更短的传输距离，提高了电化学活性，促进了快速离子扩散，并增强了赝电容行为。TLIC在50 mA g时表现出433.5 mAh g的高容量，在20 A g时具有162.1 mAh g的超高倍率性能，并且在4000次循环后具有约96%（206 mAh g）的优异容量保持率。涡轮层状晶格和赝电容存储的结合是设计具有高容量、倍率性能和长寿命等变革性性能的碳电极以用于PIBs实际应用的有效方法。
